Deep Freeze Envelops the Great White North as United States Experiences Most Unseasonably Mild Christmas on Record.
A prolonged deep freeze has enveloped a bitter and extended period of frigid weather, with readings persisting between -20C and -40C for an extended duration. On Tuesday, Braeburn in the Yukon recorded -55.7C, marking its chilliest December reading in half a century.
Enduring Chill Below -40C
Meanwhile, Mayo and Dawson endured sixteen nights in a row below -40C, with the temperature in Mayo bottoming out at -50.4 degrees Celsius at the start of the week. The capital, Whitehorse, likewise saw ten separate nights when readings fell to minus 30 degrees or lower.
This Arctic air mass pushed further southward through Christmas week. On Christmas Day, overnight temperatures in Edmonton fell below -28C.
The day after Christmas was forecast to deliver lows of at least -20C across many regions, from Edmonton in the west to Quebec in the east.
Likely to Linger For Days to Come
The frigid conditions are predicted to linger into the new year. Authorities have cautioned about potential power failures in the Yukon in the coming days, as the system endures record-high pressure from peak power usage levels.
This extended freeze is the result of the Arctic vortex settling across the northern part of the continent this month, which funnels frigid northern air southward. In the coming week, forecasts indicate this cold air will pull back northward slowly, permitting warmer Pacific winds to flow over America and reach into portions of southern Canada.
Dramatic Difference to American Heat
In stark contrast, parts of the US experienced the hottest December 25th in their history as readings skyrocketed 15 to 30 degrees Celsius above normal. Across wide regions, the atmosphere was more akin to late spring instead of the heart of winter.
Several states set Christmas Day temperature records. The capital of Oklahoma soared to 25C on Christmas Day, exceeding the old record of 22C from 1982. Urban centers like Austin, Dallas, and Charlotte, North Carolina also logged readings above 25 degrees Celsius.
High-Pressure System Sustains High Temperatures
Warmer-than-normal conditions are forecast to last on December 26th and into the weekend, with unseasonable heat forecast to sweep through the American Southeast soon.
The warmth has been fuelled by a strong upper-level ridge stretching from the southwestern deserts northward and eastward, which generates a heat-dome phenomenon. This pattern establishes a broad area of high pressure blanketing a significant part of the landmass, trapping warm air near the surface. Descending air compresses and adiabatically warms, enabling abnormally high temperatures to develop.
